The Casper Single-Door Retractable Screen is listed on Wayfair for $579.99, for example. Amazon sells a retractable door made by Genius, the same company as the Costco option, but for $365.43.

On the Harbor Freight website, over 50 people have given its Magnetic Garage Screen Door an average rating of 4 stars, with more than half of the reviewers rating it five stars, so the odds are in ...